WO2013032071A1

WO2013032071A1 - Encoding/decoding device and method using virtual view synthesis and prediction

Info

Publication number: WO2013032071A1
Application number: PCT/KR2011/010204
Authority: WO
Inventors: 이진영; 이재준
Original assignee: 삼성전자 주식회사
Priority date: 2011-08-26
Filing date: 2011-12-28
Publication date: 2013-03-07
Also published as: KR20130022923A; US20140301455A1

Abstract

The present invention relates to an encoding/decoding device and method using view synthesis and prediction. The encoding device may synthesize images corresponding to the surrounding views of a current view, encode current blocks that are included in the images of the current view, and apply a skip mode and a residual signal encoding technique.

Description

Encoding / Decoding Apparatus and Encoding / Decoding Method Using Virtual View Synthesis Prediction

One embodiment of the present invention relates to an encoding / decoding apparatus and method for encoding / decoding a 3D video, and more particularly, to applying a result of synthesizing images corresponding to a neighboring viewpoint of a current view to an encoding / decoding process. An apparatus and method are provided.

The stereoscopic image refers to a 3D image that simultaneously provides shape information about depth and space. In the case of stereo images, images of different viewpoints are provided to the left and right eyes, whereas stereoscopic images provide the same images as viewed from different directions whenever the viewer views different views. Therefore, in order to generate a stereoscopic image, images captured at various viewpoints are required.

Images taken from various viewpoints to generate stereoscopic images have a large amount of data. Therefore, considering the network infrastructure, terrestrial bandwidth, etc. for stereoscopic video, even compression is performed using an encoding device optimized for Single-View Video Coding such as MPEG-2, H.264 / AVC, and HEVC. It is almost impossible to realize.

However, since images taken at each viewpoint viewed by the observer are related to each other, there is a lot of overlapping information. Accordingly, a smaller amount of data may be transmitted by using an encoding apparatus optimized for a multiview image capable of removing inter-view redundancy.

Therefore, a multi-view image encoding apparatus optimized for generating a stereoscopic image is required. In particular, there is a need for technology development to efficiently reduce redundancy between time and time points.

An encoding apparatus according to an embodiment of the present invention comprises: a synthesized image generator configured to synthesize a first image of an already encoded neighboring view and generate a synthesized image of a virtual view; And an image encoder which encodes blocks included in the second image of the current view by using the synthesized image of the virtual view.

The encoding apparatus according to an embodiment of the present invention may further include a mode selection unit for selecting an optimal encoding mode among encoding modes related to synthesis prediction using currently defined encoding modes and the synthesized image.

An encoding apparatus according to an embodiment of the present invention sets a skip mode flag (mb_skip_flag) related to a prediction method currently defined with respect to a second image of a current view to be located in a bitstream before a flag of a first encoding mode. The apparatus may further include a flag setting unit.

According to another exemplary embodiment of the present invention, an encoding apparatus may include: a synthesized image generator configured to synthesize first images of neighboring views, which are already encoded, to generate a synthesized image of a virtual view; A mode selection unit for selecting one of a virtual view synthesis skip mode and a virtual view synthesis residual signal encoding mode associated with the synthesized image; And an image encoder which encodes current blocks included in a second image of a current view using the encoding mode.

According to another embodiment of the present invention, an encoding apparatus may include: a synthesized image generator configured to synthesize a first image of an encoded neighboring view and generate a synthesized image of a virtual view; A mode selection unit for selecting a virtual view synthesis skip mode associated with the composite image; And an image encoder which encodes current blocks included in a second image of a current view using the encoding mode.

According to another embodiment of the present invention, an encoding apparatus may include: a synthesized image generator configured to synthesize a first image of an encoded neighboring view and generate a synthesized image of a virtual view; A mode selection unit for selecting a virtual view synthesis residual signal encoding mode associated with the synthesis image; And an image encoder which encodes current blocks included in a second image of a current view using the encoding mode.

According to another embodiment of the present invention, an encoding apparatus may include: a synthesized image generator configured to synthesize a first image of an encoded neighboring view and generate a synthesized image of a virtual view; A mode selection unit for selecting an encoding mode having the best encoding performance among virtual view synthesis skip modes, virtual view synthesis residual signal encoding modes, and currently defined encoding modes associated with the synthesized image; And an image encoder which encodes current blocks included in a second image of a current view using the encoding mode.

Decoding apparatus according to an embodiment of the present invention comprises a synthesized image generating unit for generating a composite image of the virtual view by synthesizing the first image of the neighboring viewpoint already decoded; A mode determination unit that determines a decoding mode of a second image of a current view in a bitstream received from an encoding device; And an image decoder configured to decode current blocks included in the second image of the current view based on the synthesized image of the virtual view according to the decoding mode.

A decoding apparatus according to an embodiment of the present invention extracts a flag of a first decoding mode located after a flag (mb_skip_flag) of a skip mode associated with a prediction method currently defined for a second image of a current view in a bitstream. It may further include wealth.

Decoding apparatus according to another embodiment of the present invention comprises a synthesized image generating unit for generating a composite image of the virtual view by synthesizing the first image of the neighboring viewpoint already decoded; A mode determination unit that determines a decoding mode that is a virtual view synthesis skip mode associated with the composite image from a bitstream; And an image decoder configured to decode current blocks included in a second image of a current view using the decoding mode.

Decoding apparatus according to another embodiment of the present invention comprises a synthesized image generating unit for generating a synthesized image of the virtual view by synthesizing the first image of the neighboring viewpoint already decoded; A mode determination unit that determines a decoding mode that is a virtual view synthesis residual signal decoding mode associated with the composite image from a bitstream; And an image decoder configured to decode current blocks included in a second image of a current view using the decoding mode.

An encoding method according to an embodiment of the present invention comprises the steps of: synthesizing first images of neighboring viewpoints, which are already encoded, to generate a synthetic image of a virtual viewpoint; And encoding the current block included in the second image of the current view by using the synthesized image of the virtual view.

An encoding method according to an embodiment of the present invention may further include selecting an optimal encoding mode among encoding modes associated with synthesis prediction using currently defined encoding modes and the synthesized image.

An encoding method according to an embodiment of the present invention sets a flag of a skip mode related to a prediction method currently defined with respect to a second image of a current view to be located in a bitstream before a flag of a first encoding mode (mb_skip_flag). It may further comprise a step.

An encoding method according to another embodiment of the present invention comprises the steps of: synthesizing first images of neighboring views that are already encoded, generating a synthesized image of a virtual view; Selecting one of a virtual view synthesis skip mode or a virtual view synthesis residual signal encoding mode associated with the synthesis image; And encoding the current blocks included in the second image of the current view by using the encoding mode.

The encoding method according to another embodiment of the present invention comprises the steps of: synthesizing the first images of the neighboring views, which are already encoded, to generate a synthesized image of the virtual view; Selecting a virtual view synthesis skip mode associated with the synthesized image; And encoding the current blocks included in the second image of the current view by using the encoding mode.

The encoding method according to another embodiment of the present invention comprises the steps of: synthesizing the first images of the neighboring views, which are already encoded, to generate a synthesized image of the virtual view; Selecting a virtual view synthesis residual signal encoding mode associated with the synthesis image; And encoding the current blocks included in the second image of the current view by using the encoding mode.

The encoding method according to another embodiment of the present invention comprises the steps of: synthesizing the first images of the neighboring views, which are already encoded, to generate a synthesized image of the virtual view; Selecting an encoding mode having the best encoding performance among virtual view synthesis skip modes, virtual view synthesis residual signal encoding modes, and currently defined encoding modes associated with the synthesized image; And encoding the current blocks included in the second image of the current view by using the encoding mode.

A decoding method according to an embodiment of the present invention comprises the steps of: synthesizing first images of neighboring viewpoints, which are already decoded, to generate a composite image of a virtual viewpoint; Determining a decoding mode of a second image of a current view in a bitstream received from an encoding apparatus; And decoding current blocks included in the second image of the current view using the synthesized image of the virtual view according to the decoding mode.

The decoding method according to an embodiment of the present invention may further include extracting a flag of the first decoding mode located after the flag of the skip mode related to the prediction method currently defined for the second image of the current view in the bitstream. Can be.

According to an embodiment of the present invention, when encoding blocks of a current view to be encoded, a composite image of a virtual view is generated by synthesizing an image of a neighboring view, and encoding by using the synthesized image of a virtual view. The coding efficiency can be improved by eliminating it.

1 is a view for explaining the operation of the encoding apparatus and the decoding apparatus according to an embodiment of the present invention.

2 is a diagram illustrating a detailed configuration of an encoding apparatus according to an embodiment of the present invention.

3 is a diagram illustrating a detailed configuration of a decoding apparatus according to an embodiment of the present invention.

4 is a diagram illustrating a structure of a multiview video according to an embodiment of the present invention.

5 is a diagram illustrating an encoding system to which an encoding apparatus according to an embodiment of the present invention is applied.

6 is a diagram illustrating a decoding system to which a decoding apparatus is applied according to an embodiment of the present invention.

7 is a view for explaining a virtual view synthesis technique according to an embodiment of the present invention.

8 is a diagram illustrating a skip mode of a virtual view synthesis prediction technique according to an embodiment of the present invention.

9 illustrates a residual signal encoding mode of a virtual view synthesis prediction method according to an embodiment of the present invention.

FIG. 10 illustrates a flag position of a skip mode for a virtual view synthesis prediction technique according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The encoding apparatus 101 according to an embodiment of the present invention may encode 3D video and then transmit the encoded data to the decoding apparatus 102 in the form of a bitstream. The encoding apparatus 101 according to an embodiment of the present invention may improve encoding efficiency by removing redundancy between images as much as possible when encoding 3D video.

Intra, Inter, and Inter-View prediction methods may be used to remove the redundancy between the images. In addition, various coding modes (SKIP, 2NX2N, NXN, 2NxN, NX2N, and intra modes) may be used when predicting a block. Since the skip mode does not encode block information, the bit amount may be reduced compared to other encoding modes. Therefore, when more blocks are encoded in a skip mode when encoding an image, better encoding performance may appear.

According to an embodiment of the present invention, in addition to the currently defined skip mode, by defining a virtual view synthesis skip mode based on the synthetic image of the virtual view, there is a probability that more blocks constituting the current image can be encoded in the skip mode. Increases. In this case, the encoding apparatus 101 may synthesize the images of the neighboring views, which are already encoded, generate a synthesized image of the virtual view, and encode the image of the current view by using the generated synthesized image.

Hereinafter, the encoding apparatus defines a first image as an image of a current view to be encoded, a second image as an image of a neighboring view that is already encoded, and an image obtained by combining images of a neighboring view as a synthesized image. The composite image represents the same current view as the first image.

Referring to FIG. 2, the encoding apparatus 101 may include a synthesized image generator 201, a mode selector 202, a flag setter 203, and an image encoder 204.

The synthesized image generator 201 may generate the synthesized image of the virtual view by synthesizing the first images of the neighboring views that are already encoded. Here, the neighboring view means a view corresponding to the surrounding image of the second image of the current view to be encoded. The virtual view means the same view as that of the second image to be encoded.

The mode selector 202 may select an optimal encoding mode among encoding modes related to synthesis prediction by using currently defined encoding modes and a synthesized image.

For example, the mode selector 202 searches for a zero vector block located at the same position as the current block to be currently encoded in the composite image of the virtual view, and replaces the current block to be currently encoded with the zero vector block. The mode can be determined. Here, the first encoding mode may be defined as a virtual view synthesis skip mode.

The mode selector 202 searches for a zero vector block located at the same position as the current block in the composite image of the virtual view, and selects a prediction block and a prediction block most similar to the current block to be currently encoded based on the zero vector block. A second encoding mode for performing residual signal encoding may be determined based on the virtual synthesis vector indicated. Here, the second encoding mode may be defined as a virtual view synthesis residual signal encoding mode.

In addition, the mode selector 202 selects an encoding mode having the best encoding result among the first encoding mode and the currently defined third encoding modes or among the second encoding mode and the currently defined third encoding modes. The coding mode having the best coding result can be selected.

According to an embodiment, the third encoding modes may include a skip mode, inter 2N × 2N, inter 2N × N, inter Nx 2N, inter NxN, intra 2N × 2N, intra N × N, and the like. In another embodiment, the third encoding modes may include a skip mode, an inter mode, and an intra mode.

The mode selector 202 may select one of a first encoding mode, a second encoding mode, and a third encoding mode currently defined for the current block to be encoded. In this case, the mode selector 202 has the best encoding performance among the encoding results according to the first encoding mode, the encoding results according to the second encoding mode, and the encoding results according to the currently defined third encoding modes. The encoding mode can be selected. Here, the encoding performance refers to an encoding mode in which the cost function is minimum.

The flag setting unit 203 may set a skip mode flag (mb_skip_flag) related to a prediction method currently defined with respect to the second image of the current view to be located in the bitstream before the flag of the first encoding mode.

Here, the skip mode associated with the currently defined prediction method is different from the virtual view synthesis skip mode proposed in the embodiment of the present invention. A method of setting a flag will be described in detail with reference to FIG. 10.

The image encoder 204 may encode the current block included in the second image of the current view based on the encoding mode. At this time, if the encoding mode of the current block is determined as the skip mode associated with the currently defined prediction method, the encoding mode related to the synthesis prediction may be selectively applied.

Referring to FIG. 3, the decoding apparatus 102 may include a flag extractor 301, a synthesized image generator 302, a mode determiner 303, and an image decoder 304.

The flag extractor 301 may extract a flag of a first decoding mode located after a flag of a skip mode associated with a prediction method currently defined for a second image of a current view from a bitstream transmitted from the encoding apparatus 101. have. The first decoding mode will be described later.

The composite image generator 302 may synthesize the first images of the neighboring viewpoints, which are already decoded, to generate the composite image of the virtual viewpoint. Here, the neighboring view means a view corresponding to the surrounding image of the second image of the current view to be decoded. The virtual view means the same view as the view of the second image to be decoded.

The mode determiner 303 may determine a decoding mode for the second image of the current view encoded in the bitstream transmitted from the encoding apparatus 101. The decoding apparatus 102 may extract a decoding mode of the second image included in the bitstream.

For example, the mode determiner 303 searches a zero vector block located at the same position as the current block to be decoded in the composite image of the virtual view from the bitstream, and replaces the current block to be decoded with the zero vector block. The first decoding mode may be determined. Here, the first decoding mode may be defined as a virtual view synthesis skip mode.

The mode determiner 303 searches a zero vector block located at the same position as the current block to be decoded in the composite image of the virtual view from the bitstream, and currently decodes among neighboring blocks based on the zero vector block. A second decoding mode for performing residual signal decoding may be determined based on a decoded virtual synthesis vector indicating a prediction block most similar to the current block. Here, the second decoding mode may be defined as a virtual view synthesis residual signal decoding mode.

According to an embodiment of the present invention, the decoding mode of the current block included in the second image of the current view to be decoded corresponds to the encoding mode transmitted through the bitstream.

The image decoder 304 may decode the current block included in the second image of the current view by using the synthesized image of the virtual view, in which the first images of the neighboring views are synthesized according to the decoding mode.

Referring to FIG. 4, when a video of three viewpoints (Left, Center, Right) is received, a multiview video coding method of encoding GOP (Group of Picture) '8' is shown. In order to encode a multi-view image, a hierarchical B picture is basically applied to a temporal axis and a view axis, thereby reducing redundancy between images.

According to the structure of a multiview video illustrated in FIG. 4, the multiview video encoding apparatus 101 first encodes a left picture (I-view), and then a right picture (P-view) and a center picture (Center). A picture corresponding to three viewpoints can be encoded by sequentially encoding Picture: B-view.

In this case, the left image may be encoded in such a manner that temporal redundancy is removed by searching for similar regions from previous images through motion estimation. In addition, since the right image is encoded by using the previously encoded left image as a reference image, the right image may be encoded in such a manner that temporal redundancy based on motion estimation and view redundancy based on disparity estimation are removed. have. In addition, since the center image is encoded by using both the left image and the right image, which are already encoded, as a reference image, the inter-view redundancy may be removed according to the estimation of the shift in both directions.

Referring to FIG. 4, in a multi-view video encoding method, an image encoded without using a reference image of another view, such as a left image, may be encoded by predicting and encoding a reference image of another view in one direction, such as an I-View and a right image. An image that is predicted and encoded in both directions, such as a P-View and a center image, is defined as a B-View.

Frames of MVC are largely classified into six groups according to the prediction structure. Specifically, the six groups include an I-view anchor frame for intra coding, an I-view non-anchor frame for inter-time inter-coding, a P-view anchor frame for inter-view unidirectional inter coding, and a unidirectional inter-coding between views. Classified into P-view non-anchor frame for bi-directional inter-coding between time bases, B-view anchor frame for bi-directional inter-coding between views, and B-view non-anchor frame for bi-directional inter coding between time-bases. Can be.

According to an embodiment of the present invention, the encoding apparatus 101 generates a composite image of a virtual view by synthesizing a first image of a neighboring view, which is a left and right view of the current view to be encoded, and uses the synthesized image to generate a synthesized image. The second image may be encoded. Here, the first image of the neighboring view required for synthesis refers to an image that is already encoded. In detail, the encoding apparatus 101 may encode the P-View by synthesizing the already encoded I-View. Alternatively, the encoding apparatus 101 may synthesize a previously encoded I-View and a P-View to encode a B-View. As a result, the encoding apparatus 101 may encode a specific image by synthesizing the already encoded image located in the vicinity.

Referring to FIG. 5, an additional configuration for synthesizing a virtual view is required to generate a synthesized image of the virtual view. Referring to FIG. 5, in order to generate a composite image of a color image of the current view, the encoding apparatus 101 may generate a synthesized image of the color image of the current view by using the color image and the depth image of the neighboring view that are already encoded. Can be generated. In order to generate the composite image of the depth image of the current view, the encoding apparatus 101 may generate the composite image of the depth image of the current view using the depth image of the neighboring view that is already encoded.

Since the decoding apparatus 102 of FIG. 6 performs substantially the same operation as the encoding apparatus 101 of FIG. 5, a detailed description thereof will be omitted.

The synthesized image of the virtual view for the color image and the depth image may be generated using the already encoded color image, the depth image, and camera parameter information. In detail, the synthesized image of the virtual view for the color image and the depth image may be generated according to Equation 1-3.

D (x, y) means the pixel value of the pixel position (x, y) in the depth image. Znear and Zfar represent the nearest depth information and the farthest depth information, respectively.

The encoding apparatus 101 obtains the actual depth information Z, and then combines the pixel (x, y) of the current view in the world coordinate system (u, v, w) to synthesize (r) the image of the reference view into the image of the target view. ) Can be projected. In this case, the pixels (x, y) represent pixels of the color image when the virtual view synthesis is performed on the color image, and pixels of the depth image when the virtual view synthesis is performed on the depth image.

In Equation 2, A (c) denotes an intrinsic camera matrix, R (c) denotes a camera rotation matrix, T (c) denotes a camera translation matrix, and D denotes depth information.

Then, the encoding apparatus 101 projects the world coordinate system (u, v, w) into the coordinate system (x ', y', z ') of the reference image. This is done according to equation (3).

Finally, the corresponding pixel in the image of the target viewpoint becomes (x '/ z', y '/ z').

Referring to FIG. 8, the encoding apparatus 101 may generate the synthesized image 804 of the virtual view using the

first images

802 and 803 of the neighbor view of the second image 801 of the current view. That is, the composite image 804 of the virtual view has similar characteristics to the second image 801 of the current view. Here, the

first images

802 and 803 of the neighboring viewpoint are already encoded before the second image 801 of the current viewpoint is encoded and stored in the frame buffer of FIG. 5 as a reference image for the second image 801. Can be.

The encoding apparatus 101 may search for a zero vector block located at the same position as the current block in the synthesized image 804 of the virtual view, and select a first encoding mode in which the current block is replaced with the zero vector block. In practice, the first encoding mode replaces the zero vector block included in the synthesized image 804 of the virtual view without encoding the current block included in the second image 801. The first encoding mode represents a virtual view synthesis skip mode.

Referring to FIG. 9, the encoding apparatus 101 may generate the synthesized image 904 of the virtual view using the

first images

902 and 903 of the neighboring view of the second image 901 of the current view. That is, the composite image 904 of the virtual view has similar characteristics to the second image 901 of the current view. Here, the

first images

902 and 903 of the neighboring viewpoint are already encoded before the encoding of the second image 901 of the current viewpoint and may be stored as a reference image for the second image 901 in the frame buffer of FIG. 5. Can be.

The encoding apparatus 101 searches for a zero vector block located at the same position as the current block in the synthesized image 904 of the virtual view, and predicts a prediction block and a prediction block most similar to the current block to be currently encoded based on the zero vector block. A second encoding mode for performing residual signal encoding may be selected based on the virtual synthesis vector indicated.

In detail, the encoding apparatus 101 finds a block that is most similar to the current block to be currently encoded among blocks belonging to a predetermined region around the zero vector block in the synthesized image 904 of the virtual view. Here, the block most similar to the zero vector block is defined as a prediction block. The encoding apparatus 101 may determine a virtual synthesis vector indicated by the prediction block in the zero vector block. The encoding apparatus 101 may encode the difference signal between the current block and the prediction block included in the second image 901 and the virtual synthesis vector corresponding to the prediction block. Here, the second encoding mode indicates a virtual view synthesis residual signal encoding mode.

At least one of a virtual view synthesis skip mode or a virtual view synthesis residual signal encoding mode according to an embodiment of the present invention may be used together with a currently defined encoding mode.

As described above, the encoding apparatus 101 may select an encoding mode for the current block included in the second image of the current view. Here, the encoding apparatus 101 may select one of the first encoding mode, the second encoding mode, and the third encoding modes currently defined for the current block to be encoded.

In this case, the encoding apparatus 101 has the best encoding performance among encoding results according to the first encoding mode, encoding results according to the second encoding mode, and encoding results according to currently defined third encoding modes. You can select the mode. Here, the encoding performance refers to an encoding mode in which the cost function is minimum.

Here, the first encoding mode refers to an encoding mode that searches for a zero vector block located at the same position as the current block to be encoded in the synthesized image of the virtual view and replaces the current block to be encoded with the zero vector block. The first encoding mode may be defined as a virtual view synthesis skip mode.

The second encoding mode searches for a zero vector block located at the same position as the current block in the composite image of the virtual view, and indicates a prediction block and a prediction block most similar to the current block to be currently encoded based on the zero vector block. A coding mode for performing residual signal coding based on a synthesis vector. The second encoding mode may be defined as a virtual view synthesis residual signal encoding mode.

In particular, when the encoding mode is selected as the first encoding mode, the encoding apparatus 101 may identify the first encoding mode as a bit flag and transmit the first encoding mode to the decoding apparatus 102.

Referring to FIG. 10, an additional bit flag is required to use a virtual synthesis view skip mode determined according to an embodiment of the present invention. According to an embodiment of the present invention, the encoding apparatus 101 may place the flag vs_skip_flag of the virtual view synthesis skip mode after the flag mb_skip_flag of the currently defined skip mode.

If the encoding mode of the current block to be currently encoded in the second image of the current view is the skip mode of the currently defined third encoding mode, the encoding apparatus 101 sets mb_skip_flag to 1 and the decoding apparatus 102. Can be sent to. When the encoding mode of the current block to be currently encoded in the second image of the current view is the virtual view synthesis skip mode that is the first encoding mode, the encoding apparatus 101 sets mb_skip_flag to 0 and sets vs_skip_flag to 1. Can be transmitted to the decryption apparatus 102.

If the encoding mode of the current block to be currently encoded in the second image of the current view is not the skip mode that is the third encoding mode or the virtual view synthesis skip mode that is the first encoding mode, the encoding apparatus 101 sets mb_skip_flag to 0. And vs_skip_flag to 0 to transmit to the decoding device 102.

According to an embodiment of the present invention, when the optimal encoding mode for the current block of the second image of the current view is the skip mode of the third encoding mode that is currently defined, the encoding device 101 may be configured according to the present invention. According to an embodiment, the virtual view synthesis method may not be used.

Methods according to an embodiment of the present invention can be implemented in the form of program instructions that can be executed by various computer means and recorded in a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below but also by the equivalents of the claims.

Claims

A synthesized image generator configured to synthesize the first images of the neighboring views, which are already encoded, to generate a synthesized image of the virtual view; And

An image encoder which encodes current blocks included in a second image of a current view by using the synthesized image of the virtual view.

Encoding apparatus comprising a.
The method of claim 1,

A mode selection unit for selecting an encoding mode of current blocks related to synthesis prediction using the synthesized image

More,

The image encoder,

And encoding current blocks included in a second image of a current view based on the encoding mode.
The method of claim 2,

The mode selector,

And a zero vector block located at the same position as the current block included in the second image in the synthesized image of the virtual view, and determining a first encoding mode in which the current block is replaced with the zero vector block.
The method of claim 2,

The mode selector,

Search for a zero vector block located at the same position as the current block in the synthesized image of the virtual view, and predict the prediction block most similar to the current block to be currently encoded in the second image based on the zero vector block and the virtual block indicating the prediction block. And a second encoding mode for performing residual signal encoding based on the synthesis vector.
The method of claim 2,

The mode selector,

Residual signal encoding is performed based on a first encoding mode that replaces the current block with a zero vector block, a prediction block most similar to a current block to be currently encoded based on the zero vector block, and a virtual synthesis vector indicating the prediction block. And an encoding mode having a minimum cost function among the second encoding modes.
The method according to any one of claims 3 to 5,

A flag setting unit for setting a flag of a skip mode related to a prediction method currently defined with respect to the second image of the current view to be located in the bitstream before the flag of the first encoding mode.

Encoding apparatus further comprising.
The method of claim 2,

The image encoder,

And when the encoding mode of the current block is determined to be a skip mode associated with a currently defined prediction method, selectively applies an encoding mode related to synthesis prediction.
A synthesized image generator configured to synthesize the first images of the neighboring views, which are already encoded, to generate a synthesized image of the virtual view;

A mode selection unit for selecting one of a virtual view synthesis skip mode and a virtual view synthesis residual signal encoding mode associated with the synthesized image; And

An image encoder which encodes current blocks included in a second image of a current view using the encoding mode.

Encoding apparatus comprising a.
A synthesized image generator configured to synthesize the first images of the neighboring views, which are already encoded, to generate a synthesized image of the virtual view;

A mode selection unit for selecting a virtual view synthesis skip mode associated with the composite image; And

An image encoder which encodes current blocks included in a second image of a current view using the encoding mode.

Encoding apparatus comprising a.
A synthesized image generator configured to synthesize the first images of the neighboring views, which are already encoded, to generate a synthesized image of the virtual view;

A mode selection unit for selecting a virtual view synthesis residual signal encoding mode associated with the synthesis image; And

An image encoder which encodes current blocks included in a second image of a current view using the encoding mode.

Encoding apparatus comprising a.
A synthesized image generator configured to synthesize the first images of the neighboring views, which are already encoded, to generate a synthesized image of the virtual view;

A mode selection unit for selecting an encoding mode having the best encoding performance among virtual view synthesis skip modes, virtual view synthesis residual signal encoding modes, and currently defined encoding modes associated with the synthesized image; And

An image encoder which encodes current blocks included in a second image of a current view using the encoding mode.

Encoding apparatus comprising a.
A synthesized image generator configured to synthesize first images of neighboring viewpoints, which are already decoded, to generate a synthesized image of a virtual view;

A mode determination unit that determines a decoding mode of a second image of a current view in a bitstream received from an encoding device; And

An image decoder which decodes the current blocks included in the second image of the current view by using the synthesized image of the virtual view according to the decoding mode.

Decoding apparatus comprising a.
The method of claim 12,

The mode determination unit,

And a first decoding mode for retrieving a zero vector block at the same position as the current block from the bitstream in the synthesized image of the virtual view, and determining a first decoding mode in which the current block is replaced with the zero vector block.
The method of claim 12,

The mode determination unit,

Decoded virtual that searches for a zero vector block at the same position as the current block in the composite image of the virtual view from the bitstream, and indicates a prediction block most similar to the current block to be currently decoded among neighboring blocks based on the zero vector block. And a second decoding mode for performing residual signal decoding based on the composite vector.
The method of claim 13,

A flag extractor for extracting a flag of a first decoding mode located after a flag of a skip mode associated with a prediction method currently defined for a second image of a current view in a bitstream.

Decoding apparatus further comprising.
Generating a synthesized image of the virtual view by synthesizing the first images of the previously encoded neighboring views; And

Encoding current blocks included in a second image of a current view using the synthesized image of the virtual view

Encoding method comprising a.
The method of claim 16,

Selecting an encoding mode of current blocks related to synthesis prediction using the synthesized image

More,

Encoding a block included in the second image of the current view,

And a current block included in the second image of the current view based on the encoding mode.
The method of claim 17,

Selecting the encoding mode of the block,

And a zero vector block located at the same position as the current block to be currently encoded in the synthesized image of the virtual view, and determining a first encoding mode in which the current block is replaced with the zero vector block.
The method of claim 17,

Selecting the encoding mode of the block,

Search for a zero vector block located at the same position as the current block to be currently encoded in the synthesized image of the virtual view, and predict the most similar block to the current block to be currently encoded based on the zero vector block and a virtual synthesized vector indicating the prediction block. And a second encoding mode for performing residual signal encoding based on the encoding method.
The method of claim 17,

Selecting the encoding mode of the block,

Residual signal encoding is performed based on a first encoding mode in which the block is replaced with a zero vector block, a prediction block most similar to a current block to be currently encoded based on the zero vector block, and a virtual synthesis vector indicating the prediction block. A coding method, characterized in that for determining the coding mode of the minimum cost function of the second coding mode.
The method according to any one of claims 18 or 20,

Setting a flag of a skip mode related to a prediction method currently defined with respect to a second image of a current view to be positioned in a bitstream before a flag of a first encoding mode

Encoding method further comprising.
The method of claim 17,

Encoding the current block included in the second image of the current view,

And when the encoding mode of the current block is determined to be a skip mode associated with a currently defined prediction method, selectively applies an encoding mode related to synthesis prediction.
Generating a synthesized image of the virtual view by synthesizing the first images of the previously encoded neighboring views;

Selecting one of a virtual view synthesis skip mode or a virtual view synthesis residual signal encoding mode associated with the synthesis image; And

Encoding current blocks included in a second image of a current view using the encoding mode

Encoding method comprising a.
Generating a synthesized image of the virtual view by synthesizing the first images of the previously encoded neighboring views;

Selecting a virtual view synthesis skip mode associated with the synthesized image; And

Encoding current blocks included in a second image of a current view using the encoding mode

Encoding method comprising a.
Generating a synthesized image of the virtual view by synthesizing the first images of the previously encoded neighboring views;

Selecting a virtual view synthesis residual signal encoding mode associated with the synthesis image; And

Encoding current blocks included in a second image of a current view using the encoding mode

Encoding method comprising a.
Generating a synthesized image of the virtual view by synthesizing the first images of the previously encoded neighboring views;

Selecting an encoding mode having the best encoding performance among virtual view synthesis skip modes, virtual view synthesis residual signal encoding modes, and currently defined encoding modes associated with the synthesized image; And

Encoding current blocks included in a second image of a current view using the encoding mode

Encoding method comprising a.
Synthesizing the first images of the neighboring viewpoints, which are already decoded, to generate a composite image of the virtual viewpoint;

Determining a decoding mode of a second image of a current view in a bitstream received from an encoding apparatus; And

Decoding current blocks included in a second image of a current view using a synthesized image of a virtual view synthesized with first images of a neighboring view according to the decoding mode

Decryption method comprising a.
The method of claim 27,

The determining of the decoding mode for the second image of the current view may include:

And retrieving a zero vector block located at the same position as the current block to be decoded in the composite image of the virtual view from the bitstream, and determining a first decoding mode in which the current block is replaced with the zero vector block.
The method of claim 27,

The determining of the decoding mode for the second image of the current view may include:

Search for a zero vector block at the same position as the current block to be decoded in the composite image of the virtual view from the bitstream, and indicate a prediction block most similar to the current block to be currently decoded among neighboring blocks based on the zero vector block. And a second decoding mode for performing residual signal decoding based on the decoded virtual synthesis vector.
The method of claim 27,

Extracting a flag of a first decoding mode located after a flag of a skip mode associated with a prediction method currently defined for a second image of a current view in a bitstream

Decryption method further comprising.
A computer-readable recording medium having recorded thereon a program for executing the method of any one of claims 16 to 20 and 22 to 30.